The present invention relates to communications between a user equipment (UE) and a network of a wireless communication system. More specifically, the present invention relates to resource reservation protocol (RSVP) signaling in such a system.
RSVP signaling is used to make reservations for multimedia traffic originated or terminated in wireless systems. It is used to ensure the integrity and Quality of Service (QoS) for these services, especially in communications that are carried across external internet protocol (IP) networks. RSVP signaling can be originated by the UE and carried across the radio frequency (RF) interface toward the wireless network into an IP network, or it can be generated by the general packet radio service gateway support node (GGSN) which acts as RSVP proxy server on behalf of the UE. In the first case, the UE performance of RSVP signaling will consume a considerable portion of the air interface resources which can be avoided by implementing the Proxy operation in the GGSN. When the proxy function is performed by the GGSN, a negotiation mechanism is needed between the GGSN and the UE to ensure the proper operation and avoid any race conditions, where both entities simultaneously transmit RSVP signaling. A controlling module should be available to assign the RSVP signaling function, if necessary. This control module could reside in the GGSN or it can reside in the Policy control function (PCF). Lacking a clear assignment of RSVP responsibility may result in either a race condition, where both entities transmit simultaneously, or lack of any transmission of RSVP path and refresh messages to update the reservation state in routers along the reservation path. This lack of refreshment messages will result in the expiration of the reservation states and loss of allocated resources.